scholarly journals Study on performance of thrust disk as auxiliary impeller

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110284
Author(s):  
Yuxing Bai ◽  
Fei Zhao ◽  
Pan Zhou ◽  
Yijun Xu ◽  
Xin Li ◽  
...  
Keyword(s):  
Rotation Speed ◽  
Internal Cooling ◽  
Test Rig ◽  
Pump Unit ◽  
Cavitation Performance ◽  
Outlet Angle ◽  
Circulation Circuit ◽  
Vital Effect ◽  
Rotating Channel ◽  
Disk Test

Thrust disk as auxiliary impeller has a vital effect on the big power pump unit with wet motor. It can balance the axial force of the unit, provide power for internal cooling circulation circuit of motor, and further reduce the axial length of the unit. Due to the motor chamber space is limited, and the transmission medium is liquid which needs to consider the effect of cavitation, the research of thrust disk of auxiliary impeller is different from the previous studies of rotating channel. In this paper, the hydraulic performance and cavitation characteristics of thrust disk as auxiliary impeller are investigated experimentally under different conditions. A thrust disk test rig was established to obtain data under different rotation speeds and flow points. Three types of volutes with different outlet angles were designed to match the thrust disk as auxiliary impeller in experiments. Results indicate that the law of speed proportion for the traditional centrifugal pump is not applicable to the head of thrust disk as auxiliary impeller. In addition, the flow coverage increases slightly with rotation speed. Furthermore, the higher the speed is, the larger the NPSHs is, and the narrower the range of NPSH is. Besides, the smaller the outlet angle is, the higher the head of the thrust disk as auxiliary impeller is, the worse anti-cavitation performance is. The research could provide reference and guidance for the design of thrust disk as auxiliary impeller.

Effect of pin generatrix on the elastohydrodynamic lubrication performance of pin-bush pair in industrial roller chains

2021 ◽  
pp. 135065012110659
Author(s):  
Ansheng Zhang ◽  
Jing Wang ◽  
Yiming Han ◽  
Jianjun Zhang ◽  
Yi Liu
Keyword(s):  
Film Thickness ◽  
Working Condition ◽  
Elastohydrodynamic Lubrication ◽  
Test Rig ◽  
Stroke Length ◽  
Oil Supply ◽  
Supply Condition ◽  
Lubrication Performance ◽  
Custom Made ◽  
Disk Test

For industrial roller or bush chains, the bush swings relative to the pin at working condition. If proper lubrication is maintained, an elastohydrodynamic lubrication contact is formed between the pin and the bush. In this study, a custom-made pin was used to replace the steel ball of a ball-disk test rig and optical interferometric experiments were carried out to study the effect of pin generatrix on the lubrication performance. The effects of generatrix shape, stroke length and oil supply condition on the lubrication state were explored. It is found that the change of the generatrix has an important influence on the oil film thickness, especially under rare oil supply condition.

Assessment of resistance of non-metallic coatings to silt abrasion and cavitation erosion in a rotating disk test rig

Wear ◽  
1996 ◽  
Vol 194 (1-2) ◽  
pp. 149-155 ◽  
Author(s):  
J. Zhang ◽  
M.O.W. Richardson ◽  
G.D. Wilcox ◽  
J. Min ◽  
X. Wang
Keyword(s):  
Cavitation Erosion ◽  
Rotating Disk ◽  
Metallic Coatings ◽  
Test Rig ◽  
Disk Test

Effects of Lubrication on the Wear Parameters of Metals Using Pin-on-Disk Test Rig

2019 ◽  
pp. 1-12
Author(s):  
C. F. Onyeanusi ◽  
S. C. Nwigbo ◽  
N. B. Anosike ◽  
C. A. Nwajude
Keyword(s):  
Friction And Wear ◽  
Palm Kernel ◽  
Frictional Coefficient ◽  
Wear Test ◽  
Test Rig ◽  
Wear Pattern ◽  
The Coefficient Of Friction ◽  
Pin On Disk ◽  
Disk Test

Friction and wear control of movable parts in machines remain a critical challenge in the industries. Determination of measurement to control this often involves both the material and the lubricant. A wear test experiment using pin-on-disk apparatus to determine the wear pattern on a sample of aluminium and copper materials, lubricated with vegetable oil of palm kernel origin was conducted. Wear parameters, which include frictional coefficient, wear rate, and heat generation (temperature) were evaluated alongside thermal stress-strains on the pin on disk. Results showed that under the same conditions, the coefficient of friction reduces with the application of lubricant up to 84% and 7% for aluminium and copper respectively. The wear pattern for both materials when lubricated were evaluated and compared with dry condition to establish the relationships.

Isolated and Coupled Effects of Rotating and Buoyancy Number on Heat Transfer and Pressure Drop in a Rotating Two-Pass Parallelogram Channel With Transverse Ribs

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Tong-Miin Liou ◽  
Shyy Woei Chang ◽  
Yi-An Lan ◽  
Shu-Po Chan
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Pressure Drop ◽  
Turbine Blades ◽  
Internal Cooling ◽  
Cross Sectional ◽  
Gas Turbine Blades ◽  
Performance Factors ◽  
Heat Transfer Efficiency ◽  
Rotating Channel

Detailed Nusselt number (Nu) distributions over the leading (LE) and trailing (TE) endwalls and the pressure drop coefficients (f) of a rotating transverse-ribbed two-pass parallelogram channel were measured. The impacts of Reynolds (Re), rotation (Ro), and buoyancy (Bu) numbers upon local and regionally averaged Nu over the endwall of two ribbed legs and the turn are explored for Re = 5000–20,000, Ro = 0–0.3, and Bu = 0.0015–0.122. The present work aims to study the combined buoyancy and Coriolis effects on thermal performances as the first attempt. A set of selected experimental data illustrates the isolated and interdependent Ro and Bu influences upon Nu with the impacts of Re and Ro on f disclosed. Moreover, thermal performance factors (TPF) for the tested channel are evaluated and compared with those collected from the channels with different cross-sectional shapes and endwall configurations to enlighten the relative heat transfer efficiency under rotating condition. Empirical Nu and f correlations are acquired to govern the entire Nu and f data generated. These correlations allow one to evaluate both isolated and combined Re, Ro and/or Bu impacts upon the thermal performances of the present rotating channel for internal cooling of gas turbine blades.

Mixing in a Rotating Micro-Channel

2010 ◽  
Author(s):  
Wallace Woon-Fong Leung ◽  
Yong Ren
Keyword(s):  
Rotation Speed ◽  
Rectangular Cross Section ◽  
Cross Flow ◽  
Maximum Effect ◽  
Large Radius ◽  
Micro Channel ◽  
Common Channel ◽  
Rotating Platform ◽  
Channel Lengths ◽  
Rotating Channel

Mixing of liquids in rotating micro-channel is studied as it has important applications in portable diagnostic devices in rotating lab-on-a-chip. The latter utilizes rotation to pump liquid samples and reagents, and to actuate mixing between different liquids during transport in the channel using secondary flow generated from rotation. Experiments have been carried out on a rotating platform wherein two liquids are directed from their respective reservoirs through small capillaries into a common channel when the centrifugal force generated from rotation exceeds the capillary force which initially traps the liquid in their respective reservoirs. As two liquids are combined to flow through a common channel directed radially outward, Coriolis acceleration which is proportional to the rotation speed and relative radial velocity of the fluids, induces a tangential acceleration and thus velocity component that directs opposite to the direction of rotation. As this cross-flow, predominantly with maximum effect at the center of the channel, intercepts the far wall (i.e. pressure face) it splits up into two streams returning the flow back to the leading (in direction of rotation) face of the channel. This produces two main vortices/circulations for the channel and smaller vortices at the four corners for a channel with a rectangular cross-section. These vortices specifically the two main vortices are responsible for mixing of momentum, mass and energy in the cross-flow direction as the throughflow moves radially outward along the channel from small to a large radius. In the reference frame of the rotating channel, the combination of throughflow and crossflow results in two cork screw-shaped helical flow pattern streaming down the rotating channel. Connected with a microscope to view in details of the mixing in a small area, a rotating camera, mounted to the rotating platform, is used to take video of the mixing at various locations along a radial channel 30-mm in length and 1 mm width. This test is repeated for other observation locations along the channel. All the tests under identical rotation speed are grouped together to provide a full record of the mixing in the entire channel. These results can also be examined as mixing under same rotation speed but different channel lengths. Obviously, increasing length enhances mixing especially at small channel lengths under 5–10 mm. However, between 10–30 mm downstream mixing is diminished. It was also found that higher rotation speed can indeed produces better mixing with a modest increase.

Wear Characteristics of Metals Using Disk on Disk Type Wear Test Rig

2005 ◽  
Author(s):  
K. Hiratsuka ◽  
T. Yoshida
Keyword(s):  
Contact Time ◽  
Adhesive Wear ◽  
Wear Test ◽  
Test Rig ◽  
Wear Characteristics ◽  
Dissimilar Metal ◽  
Emery Paper ◽  
Type Test ◽  
Pin On Disk ◽  
Disk Test

Wear of metals is influenced by many factors such as material, surrounding atmosphere and sliding conditions. Besides these factors, type of the wear test also has a significant effect on wear results. For example, when pin on disk test rig is used, wear of disk is usually more than that of pin [1]. This is because the contact time of each specimen is asymmetric. In this case, the transfer particle at the tip of the pin protects pin against wear. So the wear of dissimilar metals depends on the pin-disk combination. In order to fully characterize the adhesive wear, we have developed a disk on disk type test rig [2]. In this rig, the circumferential surfaces of the two identical disks are in sliding contact thereby resulting in a symmetrical contact. In this paper, the wear characteristics of ten different metals sliding against emery paper as well as against themselves have been presented along with the wear of 43 dissimilar metal combinations.

Experimental Survey on Heat Transfer in a Trailing Edge Cooling System: Effects of Rotation in Internal Cooling Ducts

2012 ◽  
Author(s):  
L. Bonanni ◽  
C. Carcasci ◽  
B. Facchini ◽  
L. Tarchi
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Cooling System ◽  
Internal Cooling ◽  
Test Rig ◽  
Trailing Edge ◽  
Tip Mass

The high thermal loads, the heavy structural stresses and the small thickness required for aerodynamic performances make the trailing edge cooling (TE) cooling of high pressure gas turbine blades a critical challenge. The presented paper point out an experimental study focusing the aerothermal performance of a TE internal cooling system of a high pressure gas turbine blade, evaluated under stationary and rotating conditions. The investigated geometry consists of a 30:1 scaled model reproducing the typical wedge shaped discharge duct with one row of enlarged pedestals. The airflow pattern inside the device simulates a highly loaded rotor blade cooling scheme with a 90° turning flow from the radial hub inlet to the tangential TE outlet. Two different tip configurations were tested, the first one with a completely closed section, the second one with 5 holes on the tip outlet surfaces discharging at ambient pressure. To investigate the rotation effects on the trailing edge cooling system performance, a rotating test rig was purposely developed and manufactured. The test rig is composed by a rotating arm that holds the PMMA TE model and the instrumentation. A thin Inconel heating foil and wide band Thermo-chromic Liquid Crystals are used to perform steady state heat transfer measurements. A rotary joint ensures the pneumatic connection between the blower and the rotating apparatus, moreover several slip rings are used for both instrumentation power supply and thermocouple connection. Heat transfer coefficient measurements were made with fixed Reynolds number close to 20k in the hub inlet section and with variable rotating speed in order to set the Rotation number from 0 (non rotational test) up to 0.3. Six different configurations were tested: two different tip mass flow rates (the first one with a completely closed tip, the second one with the 12.5% of the inlet flow discharged from the tip) and three different surface conditions: the first one consists in the flat plate case and the others in two ribbed cases, with different angular orientation (60° and −60° respect to the radial direction). Results are reported in terms of detailed heat transfer coefficient 2D maps on the suction side surface as well as span-wise profiles inside the pedestal ducts. The reported work has been supported by the Italian Ministry of Education, University and Research (MIUR).

A Two-Disk Test Rig for Researching the Damage Behavior of Rolling/Sliding Contact Surfaces under Extreme Conditions

2011 ◽  
Vol 291-294 ◽  
pp. 1500-1505
Author(s):  
Bo Peng ◽  
Li Qin Wang ◽  
Shou Xiao Fan ◽  
De Zhi Zheng ◽  
Le Gu
Keyword(s):  
Surface Damage ◽  
Hydraulic Cylinder ◽  
Sliding Contact ◽  
Hertzian Contact ◽  
Variable Load ◽  
Extreme Conditions ◽  
Test Rig ◽  
Speed Up ◽  
Main Spindle ◽  
Disk Test

A two-disk test rig researching surface damage and ultimate performance of rolling-sliding tribo-parts in extreme conditions is designed. Variable speed (rolling speed up to 83.6m/s, sliding speed up to 16.4m/s) of the rolling/sliding contact are input by motor spindle and regulated with gear. Variable load (Hertzian contact up to 4GPa) is applied with hydraulic cylinder. High temperature (~+300°C) and cryogenic environment(liquid nitrogen) is implemented by changing the lubricant condition. Thermal-stress analysis with ANSYS shows that the temperature and stress of the tester body is reasonable. As the signals judging failure, such parameters as temperature and vibration of the supporting bearing, power consumption of the main spindle, temperature of the tribo-parts surface are monitored in real time. Kingview, PLC, VB and MATLAB software are employed in the online monitoring system to collect data automatically. Types of tribo-parts were tested in the test rig, getting their ultimate performance and the effect of each parameter on surface damage.

Experimental and Numerical Analysis of the Flow Structure and Dust Separation Inside a Pre-Swirl Cooling Air System

2003 ◽  
Author(s):  
O. Schneider ◽  
H. J. Dohmen ◽  
F.-K. Benra ◽  
D. Brillert
Keyword(s):  
Numerical Analysis ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Internal Cooling ◽  
Flow Conditions ◽  
Test Rig ◽  
Complex Flow ◽  
Air System ◽  
Cooling Air

Improvements in efficiency and performance of gas turbines require a better understanding of the internal cooling air system which provides the turbine blades with cooling air. With the increase of cooling air passing through the internal air system, a greater amount of air borne particles is transported to the film cooling holes at the turbine blade surface. In spite of their small size, these holes are critical for blockage. Blockage of only a few holes could have harmful effects on the cooling film surrounding the blade. As a result, a reduced mean time between maintenance or even unexpected operation faults of the gas turbine during operation could occur. Experience showed a complex interaction of cooling air under different flow conditions and its particle load. To get more familiar with all these influences and the system itself, a test rig has been built. With this test rig, the behavior of particles in the internal cooling air system can be studied at realistic flow conditions compared to a modern, heavy duty gas turbine. It is possible to simulate different particle sizes and dust concentrations in the coolant air. The test rig has been designed to give information about the quantity of separated particles at various critical areas of the internal air system [1]. The operation of the test rig as well as analysis of particles in such a complex flow system bear many problems, addressed in previous papers [1,2,3]. New theoretical studies give new and more accurate results, compared to the measurements. Furthermore the inspection of the test rig showed dust deposits at unexpected positions of the flow path, which will be discussed by numerical analysis.

Performance Analysis of a Low-Power Tangential Flow Turbine With Rotary Channel

2005 ◽  
Vol 127 (4) ◽  
pp. 272-279 ◽  
Author(s):  
Silvio Barbarelli ◽  
Gaetano Florio ◽  
Nino Michele Scornaienchi
Keyword(s):  
Performance Analysis ◽  
Flow Rate ◽  
Data Acquisition System ◽  
Automated Measurement ◽  
Operating Characteristics ◽  
Test Rig ◽  
Tangential Flow ◽  
Experimental Campaign ◽  
Brake Power ◽  
Rotating Channel

A tangential flow prototype turbine with a rotating channel containing five optimized deflectors is presented. This atypical turbine configuration may be useful for application in the low ns high ds region of the Balje chart, where conventional turbines offer very poor performances. A 70kW maximum brake power, pressured-air test rig has been used for the analysis of operating characteristics, such as pressure, temperature, flow rate, and brake power. An electronic data acquisition system for automated measurement management was employed. An experimental campaign was carried out to identify the distribution of the pressure in the rotary ducts of the turbine. The results indicate the presence of a pressure gradient in the immediate vicinity of the inlet jet that is strongly attenuated when the ducts are not directly in contact with the jet.

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